Analytical model and numerical simulations for solid propellant using a Random Loose Packing approach

Due to the powder nature of a solid rocket propellant, a better understanding of the packing structure is needed. In this study, a constructive algorithm in order to simulate the Random Loose packing process, is developed, and it is an improvement of the classical, so called, dropping and roll method. In particular, the final position of each sphere is determined solving an analytical model, and it leads to better accuracy in the final results. Moreover, this algorithm can be applied not just to a mono-sized sphere packing, but each sphere can have a different radius. Furthermore, a 2D map is created in order to find the volume fraction for bi-modal propellant function of the radius ratio and different percentage of each components. Also the contact number behavior (related with the inner structure) is analyzed.